The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, t...The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, the accumulation of IGs in different parts of plants and upon treatment with plant hormones were analyzed in A. thaliana seedlings. It was shown that MYB34, MYB51, and MYB122 act together to control the biosynthesis of 13M in shoots and roots, with MYB34 controlling biosynthesis of IGs mainly in the roots, MYB51 regulating biosynthesis in shoots, and MYB122 having an accessory role in the biosynthesis of IGs. Analysis of glucosinolate levels in seedlings of myb34, myb51, myb122, myb34 myb51 double, and myb34 myb51 myb122 triple knockout mutants grown in the presence of abscisic acid （ABA）, salicylic acid （SA）, jasmonate （JA）, or ethylene （ET） revealed that： （1） MYB51 is the central regulator of IG synthesis upon SA and ET signaling, （2） MYB34 is the key regulator upon ABA and JA signaling, and （3） MYB122 plays only a minor role in JA/ET-induced glucosinolate biosynthesis. The myb34 myb51 myb122 triple mutant is devoid of IGs, indicating that these three MYB factors are indispensable for IG production under standard growth conditions.展开更多
Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytoch...Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.展开更多
文摘The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, the accumulation of IGs in different parts of plants and upon treatment with plant hormones were analyzed in A. thaliana seedlings. It was shown that MYB34, MYB51, and MYB122 act together to control the biosynthesis of 13M in shoots and roots, with MYB34 controlling biosynthesis of IGs mainly in the roots, MYB51 regulating biosynthesis in shoots, and MYB122 having an accessory role in the biosynthesis of IGs. Analysis of glucosinolate levels in seedlings of myb34, myb51, myb122, myb34 myb51 double, and myb34 myb51 myb122 triple knockout mutants grown in the presence of abscisic acid （ABA）, salicylic acid （SA）, jasmonate （JA）, or ethylene （ET） revealed that： （1） MYB51 is the central regulator of IG synthesis upon SA and ET signaling, （2） MYB34 is the key regulator upon ABA and JA signaling, and （3） MYB122 plays only a minor role in JA/ET-induced glucosinolate biosynthesis. The myb34 myb51 myb122 triple mutant is devoid of IGs, indicating that these three MYB factors are indispensable for IG production under standard growth conditions.
文摘Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.
